iscsi-target: Re-add chunk from backport of upstream 79d59d08 to 3.10

Commit d5c55fa3, the backport of upstream 79d59d08
("iscsi-target: Fix wrong buffer / buffer overrun in
iscsi_change_param_value()") left out applying one chunk of the fix in
iscsi_login_non_zero_tsih_s2().  Add the missing chunk.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/target/iscsi/iscsi_target_login.c

@@ -597,13 +597,8 @@ static int iscsi_login_non_zero_tsih_s2(
 	 *
 	 * In our case, we have already located the struct iscsi_tiqn at this point.
 	 */
-	memset(buf, 0, 32);
-	sprintf(buf, "TargetPortalGroupTag=%hu", ISCSI_TPG_S(sess)->tpgt);
-	if (iscsi_change_param_value(buf, conn->param_list, 0) < 0) {
-		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
-				ISCSI_LOGIN_STATUS_NO_RESOURCES);
+	if (iscsi_change_param_sprintf(conn, "TargetPortalGroupTag=%hu", sess->tpg->tpgt))
 		return -1;
-	}
 
 	return iscsi_login_disable_FIM_keys(conn->param_list, conn);
 }